ESA Confirms Ariane 6 Block 3 Upgrades Have Been Shelved - European Spaceflight
The European Space Agency has confirmed to European Spaceflight that it is no longer considering the Ariane 6 Block 3 evolution, saying there is “no programme need or justification” for the evolution at this time. A key element of this now-scrapped evolution of Ariane 6 was the ICARUS lightweight upper stage. “No evolution of the ULPM [ICARUS] was approved at CM25, as no programme need was identified for such an evolution at this stage.
The European Space Agency has confirmed to European Spaceflight that it is no longer considering the Ariane 6 Block 3 evolution, saying there is “no programme need or justification” for the evolution at this time.
Questions regarding the scrapping of the Block 3 upgrades arose earlier this month after SpaceScout reported that an ESA study team had been told Ariane 6 Block 2 would be the rocket’s final major version, forcing it to rework a proposed Enceladus mission, a planned probe to Saturn’s icy moon, that had been based on the more capable Block 3 variant of the four-booster Ariane 64 rocket. A key element of this now-scrapped evolution of Ariane 6 was the ICARUS lightweight upper stage.
In emailed responses to questions from European Spaceflight, an ESA spokesperson said the near-term roadmap for Ariane 6 upgrades includes the already introduced P160C boosters and a lighter Vulcain Aft Bay to “increase launcher performance and competitiveness.” This will be followed by the introduction of the Astris orbital transfer vehicle (OTV) around 2029, which the spokesperson said would “bring significant additional capabilities to the Ariane 6 ecosystem.”
While the presentation slide was unequivocal in stating that Ariane 6 would “not be developed further,” the ESA spokesperson was less definitive about the rocket’s longer-term evolution, which could include upgrades necessary for human spaceflight capability.
“Ariane 6 will continue to evolve whenever new mission requirements justify further developments,” said the spokesperson. “Human spaceflight is also being considered in the context of developing a future European capability to send astronauts to space aboard a European vehicle launched from European territory.”
The spokesperson was, however, more explicit about the near-term fate of the ICARUS lightweight upper stage.
“No evolution of the ULPM [ICARUS] was approved at CM25, as no programme need was identified for such an evolution at this stage. Consequently, no development activities are currently underway.”
ICARUS was a proposed lightweight Ariane 6 upper stage that would have made extensive use of carbon-composite structures developed under ESA’s technology programme. As recently as October 2025, ESA was still describing PHOEBUS carbon-fibre tanks as having a “potential future application on Ariane 6.” A month later, however, member states decided not to approve an evolution of the Ariane 6 upper stage.
During the ESA Ministerial Council meeting in November 2025 (CM25), the agency had proposed a €304.4 million envelope for the Ariane 6 adaptations element. Member states ultimately committed just €145.94 million, leaving €158.46 million uncovered, a 52% shortfall. The agency’s breakdown of the funding received for this element, however, does not specify which Ariane 6 upgrades were included in the unfunded portion of the envelope.
The ESA spokesperson did not tie the funding shortfall to the Block 3 decision, framing it instead as a matter of programme need. But the timing is notable. Member states committed less than half of the requested Ariane 6 adaptations envelope at the same Ministerial Council meeting at which the evolution was shelved.